Extreme conformity to sex-role stereotypes has been associated with behavioral, emotional and cognitive difficulties in children and adults. The proposed research is a series of experimental and correlational studies designed to 1) examine directly the effects of sex-typed play on the basic cognitive skills of preschoolers, 2) evaluate the effectiveness of an early intervention program on the sex-type play preferences and behavior patterns of preschoolers 3) refine and validate a measure of cognitive sex-role flexibility in preschool and school-aged children, and 4) relate cognitive and behavioral measures of sex-typing to measure of mental health and cognitive skills of preschoolers and school-aged children. The effects of play with traditionally male-preferred toys on visual-spatial skills will be assessed by examining children's response to a learning program employing a set of such toys. The experimental manipulations in the intervention program involve the use of a set of classroom techniques developed and evaluated individually in earlier studies. Measures of sex-role flexibility and gender salience will employ a ranking procedure which will permit the identification of androgynous children, as well as traditionally sex-typed and cross sex-typed children.